A case of mistaken identity could mean that Muhammad Makkawi, another Egyptian, was instead detained.

Saif Al-Adel, a suspected terrorist wanted in connection with the 1998 bombings of the United States Embassies Tanzania and Kenya, is shown in a photo released by the FBI October 10, 2001 in Washington, DC. Courtesy FBI/Getty Images. (AFP/Getty Images)

A 2011 article in Asharkh Alawsat said the confusion over the identities of the two men is due to the similarity of their backgrounds: "both figures are former Egyptian army officers who left the army to join Ayman al-Zawahiri's Egyptian Islamic Jihad group [EIJ], and both figures fought alongside the mujahedeen during the Soviet occupation of Afghanistan."

GlobalPost correspondent Erin Cunningham tweeted from Cairo that the man detained was Muhammad Makkawi, a former member of the Egyptian Islamic Jihad who had allegedly sought political asylum in Pakistan.

MOI source just told me that it is NOT Saif al-Adel that was arrested at Cairo airport, but Mohamed Ibrahim Makkawi.

Al-Adel was believed to have been detained under house arrest in Iran after the US-led invasion of Afghanistan in 2001, though the BBC said that Iran never acknowledged this.

Recent rumors indicated that al-Adel had been released and had traveled to northern Pakistan. After Al Qaeda announced his ascension in early May 2011, he became interim leader of the organization, CNN reported. He reportedly flew on Emirates from Pakistan, through Dubai, to Cairo, where he was arrested.

AFP reported that al-Adel is a former Egyptian special forces officer and was arrested after he attempted to pass through customs. Al-Adel is wanted by the US in connection with the 1998 African embassy bombings, according to the FBI. Up to $5 million could be rewarded for his capture.